1. Field of the Invention
The present invention refers to a device intended to inject, into humans and animals, solutions for therapeutic or diagnostic purposes. The device already contains the fluid for injection, and is ready for use. The device is disposable, thereby eliminating the need for conventional glass vials, bottles or ordinary syringes.
2. Discussion of the Related Prior Art
Presently, injectable solutions, including pharmaceuticals and contrast media, are available in glass vials, transferred, at the time of administration, to glass or plastic syringes. Syringes already containing contrast media and some pharmaceuticals, ready for use, are also available. Another available device is the pressure injection pistol, usually for vaccines administration through the skin.
Conventional syringes present many recognized disadvantages, as the need to fill the syringe from a separate vial, an uncomfortable and time consuming process, including the risk of contamination and, in many cases, the plunger can be difficult, to manipulate, requiring, in many situations, high pressures on the plunger, as in the use of high viscosity media; in other cases, the volume is to be high, requiring long plungers difficult to operate. In this regard, it has been developed a pre-filled syringe for contrast media with volumes ranging from 50 to 100 ml with a plunger too long to be comfortably operated by practitioners. In addition, pre-filled syringes, including those with therapeutic fluids, have to be manufactured under expensive and too rigid standards to avoid the risk of leakages and contamination. In the case of infusion protocols, a bottle or a bag containing the solution to be administered must be connected to the infusion tubing, by insertion of the tubing spike through the stopper in the bottle or to the connection in a bag requiring some dexterity, being also uncomfortable. Presently, many automated devices to drive conventional syringes are also available, requiring, however, the use of tubings, presenting high cost and usage limited to selected places.
Many attempts have been made to provide alternative devices to the conventional syringes and related fluid administration devices, to overcome their disadvantages.
One type of approach has been to provide an injector system with a pre-filled collapsible reservoir with precisely measured amounts of medication. These devices have flexible walls, so that the contents can be discharged by compressing or squeezing them.
Devices of this type are exemplified in the following U.S. Pat. Nos.:
______________________________________ U.S. Pat. No. Patentee ______________________________________ 789,093 Dean 1,222,814 Storz 2,618,263 Lakso, et al. 3,099,264 Hubbard 3,114,369 Hall 4,013,073 Cunningham 4,018,222 McAleer et al. 4,130,117 Van Eck 4,475,906 Holzner 4,581,021 Landau et al. 4.955,871 Thomas 5,261,881 Riner ______________________________________
While the above listed prior art devices avoid, in varying degrees, the aforementioned problems associated with plunger-type syringes, they did not find widespread application due to several reasons, as, for example, difficulties in self-injection situations, specially for the physically feeble or diabetics, some present the inability to be used with disposable needles or connector tubings, and in devices provided with needle some mechanism must be included to prevent fluid escape during storage before use, and in the majority of devices of these types, their structural principles are associated with complexity for manufacturing and cost. Another problem with some devices of the type considered is the type of plastic material of the container presenting a tenency to return to its original shape, known as memory, when the applied pressure is relaxed causing introduction of air or tissue aspiration.
Otherwise, regarding the plunger-type syringes, there are situations in which large number of injections have to be performed, as in hospitals, emergency suites and mass vaccination procedures, over a short period of time, when it is virtually impossible to avoid the risk of contamination due to reuse or the many necessary steps for preparation.
Another problem of many such proposed devices is that the fluid container is conceived to be pressed directly by fingers, causing the risk of fluctuations in the injection rate, oscillations of the device, with potential increased trauma to vessel or tissue.
As a result, there has been a need for safer, easier to operate, lower costs medication administration systems, including the low dose, high dose with pressure and infusion devices.
Aiming to present an easier to use and more cost effective alternative to conventional systems, and other devices as those in the above listed patents, it has been developed the present medication injection device and its accessories, seeking to overcome most of disadvantages of prior art devices, wherein the preferred embodiment comprises a squeezable fluid container made, preferably, by two films of a neutral, flexible, pressure resistant and autoclavable plastic material, heat-sealed at the edges, attached to a luer-lock connection, the fluid being propelled, in the small volumes injector, by a pressure applied by fingers, on both sides of the container, on a pair of rigid plastic plates, in this way better distributing the force on the surface, resulting in a stable, ready and easier to use and comfortable to medical practitioners, the same being with large volumes pressure injections deice and even with the infusion package.
Although the invention has been described and detailed according to the preferred embodiment and the concretions here inserted, many modifications and variants can be made on the same, according to the appended claims.